The unceasing incidence of heavy and other metal pollution of the waterways and the environment is leading to increased adverse health effects on the general population, and the fines generally levied on the polluters do not resolve the persistent effects on the poisoned environment nor do these heal the people injured by such incidents. A more meaningful approach would be an effort to capture such pollutants at the source of generation. Separately, lubricating agents are base oils and additives used in lubricant formulations for engine oil, hydraulic fluids, gear oils, metal working fluids, and other applications, and consumers are seeking new and advantageous lubricating agents.
The use of vegetable oils as a source of renewable feedstock has been investigated as possible renewable feedstocks in nonfood applications (Harry-O'kuru, R. E., et. al., JAOCS, 82(3): 207-212 (2005); Harry-O'kuru, R. E., et. al., Ind. Crops and Prod., 15: 51-58 (2002); Harry-O'kuru, R. E., et al., J. Agric. Food Chem., 50: 3214-3221 (2002)). Vegetable oils typically have a triacylglycerol structure with a glycerol backbone connected to three long-chain ester linkages. The hydrocarbon chains of the structure make the molecule hydrophobic and immiscible with water or lower alcohols. The ester groups and internal double bonds give ample routes for modification (Gunstone, E., et al., Fatty Acid and Lipid Chemistry, Blackie Academic and Professional, Glasgow, U K, 1994). A wide variety of such vegetable oil derivatives having a variety of applications have been reported (Biermann et al., Angew. Chem. Int. Ed., 39: 2206-2224 (2000); Biermann et al., Angew. Chem. Int. Ed. Engl., 50: 3854-3871 (2011); Hwang et al., J. Am. Oil. Chem. Soc., 80: 811-815 (2003); Sharma et al., Bioresource Technol., 99: 7333-7340 (2008); Ionescu et al., J. Serbian Chem. Soc., 76: 591-606 (2011); Biswas et al., J. Agric. Food Chem., 56: 5611-5616 (2008); Biswas et al., Green Chem., 9: 85-89 (2007); Biswas et al., J. Agric. Food Chem., 57: 8136-8141 (2009)).
A vegetable oil of particular interest to us is a polyhydroxyl vegetable oil inasmuch as the oil has stable emulsifying properties for oil in water emulsions (Harry-O'kuru, R. E., et. al., Ind. Crops and Prod., 15: 51-58 (2002)). We believe that it would be advantageous to further modify these polyhydroxyl oils given that the feedstock material is renewable and plant based. One area of possible modification is introducing an amine function group to the oil. We synthesized α-hydroxyamine triglycerides via the oxirane triglyceride (Harry-O'kuru, R. E., et al., Ind. Crops and Prod., 15: 51-58 (2002)). Then we investigated modifications of the polyhydroxy triglyceride since it would be advantageous to further explore the functional properties of a poly (vicinal diamine) vegetable oil. Vegetable oil precursors are typically converted according to the reaction sequence:
vegetable oil triglyceride→epoxidized vegetable oil triglyceride→polyhydroxy triglyceride→polyketone triglyceride→polyimine triglyceride→polyamine triglyceride
Hence, precursor of the polyhydroxy triglycerides typically involve vegetable oil epoxidation and epoxy hydrolysis reaction steps well known in the art. Typically, epoxidations are done commercially with peroxide reagents such as peracetic acid or the formic acid/hydrogen peroxide reagent. Epoxidized soybean oil is commercially manufactured (for example by Arkema and others). Hydrolysis of the epoxide can be done by acid catalyzed ring opening of the epoxide with water, thereby producing polyhydroxy triglycerides.
We have found that renewable resources in the form of vegetable oils which we have chemically modified to polyketone, polyamine, and polyimine triglyceride derivatives are capable of sequestration of toxic metal species from aqueous media. Use of these agents at the generation site of the metal species will remediate the effluents containing the toxicants and thus result in a cleaner, safer environment. The polyketone triglycerides, polyamine triglycerides, and polyimine triglycerides also are biodegradable lubricating agents.